Or maybe that the improvements require a complex set of seemingly unrelated changes to occur.

For example, Adam Smith explained that the main driving force of change at some point was the appearance of new things to buy for the very rich people, as this allowed a novel redistribution of wealth and power.

(I am not quoting the ful argument here, and I am not claiming that the described factor was the only driving force of change, or even that I can claim on my own that it was the main force)